Carpet waste composite

ABSTRACT

A composite material is produced from carpet waste and a binding agent, in intimate association, and may also include wood fiber or chips and/or other additives. A method of manufacturing a composite material includes shredding carpet waste, coating the carpet waste with a binding agent, and subjecting the shredded, coated carpet waste to elevated heat and pressure. As an additional step, the composite material may be actively cooled to prevent deformation of the material.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority to U.S.application Ser. No. 16/382,697, filed Apr. 12, 2019, which is acontinuation of and claims priority to U.S. application Ser. No.15/472,806, filed Mar. 29, 2017, which is a continuation of and claimspriority to U.S. application Ser. No. 14/339,991, filed Jul. 24, 2014,which is a continuation of and claims priority to U.S. application Ser.No. 13/597,481, filed Aug. 29, 2012, which is a continuation of andclaims priority to U.S. application Ser. No. 13/053,837, filed on Mar.22, 2011, which is a continuation of and claims priority to U.S.application Ser. No. 11/846,865, filed on Aug. 29, 2007, which is acontinuation-in-part application of and claims priority to U.S.application Ser. No. 11/514,303, filed on Aug. 31, 2006, which is acontinuation-in-part of and claims priority to U.S. application Ser. No.11/507,366, filed on Aug. 21, 2006, which claims priority to U.S.Application Ser. No. 60/760,500, filed on Jan. 20, 2006, all of whichare hereby incorporated by reference herein in their entireties.

FIELD OF THE INVENTION

This invention relates to systems and methods for fabricating plasticcomposites (PCs) and, more particularly, to systems and methods forplastic composites that employ recycled carpet waste as a component ofthe composite.

BACKGROUND OF THE INVENTION

Natural and manmade composites can be used in building construction,industrial applications, consumer goods, automotive products, and otherindustries requiring moisture or thermal resistance with variousphysical properties, such as low moisture absorbance and low thermaldistortion. The ability to build composites of this nature, whilecontrolling physical properties such as strength, stiffness, ductility,impact resistance, and hardness, opens a variety of applicationopportunities. PCs, however, may be expensive to produce, due in part tothe high cost of virgin thermoplastic materials used therein. While useof PCs may be desirable as an alternative to natural wood products tolimit the depletion of timber resources, the high cost of PCs comparedto wood products may limit their use. Moreover, manufacturing PCsrequires the manufacturing of even more virgin plastics, thus presentingan additional environmental problem.

There exists growing pressure to re-utilize waste streams which are highin volume and low in degradability. In particular the manufacture,installation, use and (eventually) replacement of floor coveringproducts, especially carpeting, produces a large amount of wasteproduct. Carpet waste from new carpet production, post-consumer landfillor other used carpet applications, is a several billion pound-per-yearwaste problem. Often, carpet waste is not recycled, but rather isdisposed of by land-filling or burning, with the obvious attendantenvironmental and cost concerns.

What is needed, then, is a plastic composite that may still functionacceptably in a variety of applications, while being inexpensive tomanufacture, due to incorporation of readily available waste products.

SUMMARY

In one aspect, the invention relates to a composite adapted for use as abuilding material, the composite including processed carpet waste,between about 2% and about 10% binding agent by weight of the composite,and between about 20% and about 30% natural fibers by weight of thecomposite in intimate association with the recycled carpet waste and thebinding agent. In an embodiment of the above aspect, the compositeincludes about 5% binding agent, by weight. In another embodiment, thecomposite has about 30% natural fibers, by weight. In certainembodiments of the above aspect, the processed carpet waste includes amaterial selected from the group consisting of wool, nylon, polyester,polypropylene, jute, sisal, and combinations thereof. In certainembodiments of the above aspect, the natural fibers are selected fromthe group consisting of wood chips, wood flour, wood flakes, sawdust,flax, jute, hemp, kenaf, rice hulls, abaca, and combinations thereof.

In yet another embodiment of the above aspect, the composite includes anadditive selected from the group consisting of a colorant, a fireretardant, a fiberglass, a mold inhibitor, and combinations thereof. Incertain embodiments, the processed carpet waste is at least one ofpost-industrial waste and post-consumer waste. In other embodiments ofthe above aspect, after submersion testing according to ASTM D1037-96A,the composite exhibits water absorption of not more than about 3%, byweight. Other embodiments of the composite include processed carpetwaste having a melted polypropylene and an unmelted nylon. In certainembodiments, the processed carpet waste is at least one of a pelletizedcarpet waste and a fiber carpet waste.

In another aspect, the invention relates to a method of manufacturing acomposite adapted for use as a building material, the method includingthe steps of applying heat and pressure to a processed carpet waste anda binding agent to form the composite material, and cooling thecomposite material while applying pressure to the composite material.This aspect may include the step of processing carpet waste, wherein theprocessing step is at least one of chopping, shredding, grinding,contaminant separating, palletizing, agglomerating, pulverizing, finegrinding, and fiberizing the carpet waste. In some embodiments of theabove aspect, the step of applying heat and pressure occurs in a firstcycle press, and wherein the step of cooling the composite whileapplying pressure occurs in a second cycle press. In other embodiments,the step of applying heat and pressure and the step of cooling thecomposite while applying pressure occur in a first cycle press. In stillother embodiments of the above aspect, the step of applying pressureheats the composite material to a temperature of about 100° F. to about600° F., to a temperature of about 200° F. to about 550° F., to atemperature of about 340° F. to about 420° F., or to a temperature ofabout 420° F. to about 500° F. In yet another embodiment, the step ofcooling the composite material while applying pressure cools thecomposite material to a temperature of about 300° F. to about 32° F., orto a temperature of about 250° F. to about 180° F., or to a temperatureof about 80° F.

In another embodiment of the above aspect, the pressure applied duringthe applying heat step and the cooling step is substantially constant.Certain embodiments may include the processed carpet waste as anunmelted carpet waste. Additional embodiments include the step of mixingthe processed carpet waste and the binding agent. In some embodiments ofthe above aspect, the composite has about 90% to about 98% processedcarpet waste, by weight, or about 95% processed carpet waste, by weight.In another aspect, the invention relates to a composite buildingmaterial manufactured according to the processes described above.

DESCRIPTION OF DRAWINGS

Other features and advantages of the present invention, as well as theinvention itself, will be more fully understood from the followingdescription of the various embodiments, when read together with theaccompanying drawings, in which:

FIG. 1 is a perspective view of a plastic composite fabricated inaccordance with one embodiment of the present invention;

FIG. 2 is a flow chart depicting the types of size reduction equipmentand the variety of size reduction procedures depending on the finalcarpet waste material form desired for the process equipment;

FIG. 3 depicts steps for coating the processed carpet waste material abonding agent and subsequent forming process to produce the plasticcomposite product; and

FIG. 4 depicts steps for finishing the plastic composite product.

DETAILED DESCRIPTION

The new systems and methods can be used to process and combine recycledcarpet waste with a binding agent to form a PC with equivalentproperties to those PCs made with virgin plastics at reduced cost.

FIG. 1 shows one embodiment of a sheet or board plastic composite 10including recycled carpet waste formed in accordance with the presentdisclosure. The composite 10 is generally a dimensional composite body12 formed from a mixture including recycled carpet waste and a bindingagent. Length L, width W, and thickness t, of the composite 10 aredictated by the production machinery used. Functional performanceparameters of the composite 10 may be defined in part by the amount ofcarpet waste, binding agent, natural fillers, and other optionaladditives. In general, however, the density of the composite 10 isdirectly related to the total amount of carpet waste used and the finalthickness t of the board. The recycled carpet waste, which may beblended or dispersed with natural fillers within the fiber-polymercompound, results in a composite having physical properties equivalentto PCs made with virgin thermoplastics. The recycled carpet waste may beprocessed into a fiber fluff, or other form, from post-industrial orpost-consumer carpet waste. Depending on the composition of the carpetused, the recycled carpet waste can include wool, nylon, polyester,polypropylene, jute, sisal, like materials, and combinations thereof.Due at least in part to processing controls, described in greater detailin the following paragraphs, the recycled carpet waste is dispersed anddistributed substantially uniformly throughout the composite 10. Variousbinding agents may be utilized as desired for a given application.Certain embodiments of a PC made in accordance with the presentinvention utilize methylenediphenyldiisocyanate (MDI). MDI acts as abinding agent for the fibers or agglomerated carpet waste materials tocontribute to the structural integrity of the composite products. As analternative to MDI, binding can be accomplished using urea formaldehyde(UF), melamine urea formaldehyde (MLTF), phenol formaldehyde (PF),similar binding agents, and combinations of agents.

In addition to the binding agent, the composite 10 may incorporatenatural fibers to help provide the composite with the appearance andfeel of a natural wood product. Types of natural fibers, such as woodfillers or the like, include wood chips, wood flour, wood flakes, woodshavings, sawdust, flax, jute, abaca, hemp, kenaf, rice hulls, likematerials, and combinations thereof. The sizes of the various naturalfibers is not critical and may range from that of sawdust and woodflour, up to and exceeding 1″ long wood chips, though fibers and chipsless than about 0.5″ may be preferred. The composite may includeadditives such as colorants, lubricants, flame retardants,compatiblizers, coupling agents, other materials, and combinationsthereof. The relative amounts of components (i.e., recycled carpetwaste, filler, additives, etc.) may be modified as desired for aparticular application. The various component amounts, ratios ofcomponents, and finished composite properties in certain embodiments,are described in more detail below.

Unless otherwise noted, the use of one material when describing aparticular application, process, or embodiment does not limit thedescribed application, process, or embodiment to the specific materialidentified. The materials may be used interchangeably, in accordancewith the described teachings herein. Moreover, the terms “PCs,”“composite sheets,” and the like, are used interchangeably herein todescribe plastic composite boards or sheets made from recycled carpetwaste which may include additional additives. In addition to PCs, othercomposite products may be manufactured utilizing, in whole or in part,recycled carpet waste. A non-limiting list of such composite productsinclude plastic piping, molded articles such as flower pots or seedingtrays, building siding or roofing, fencing, furniture, or other types ofextruded, injection molded, and/or compression molded products.

FIG. 2 shows the types of equipment and the variety of procedures forcarpet waste size reduction, depending on the final form desired for theprocess equipment. The final form may also be dependent on the desiredfinished composite product and physical or visual appearance properties.In short, the carpet waste is processed as described below to reduce itssize. Then the size-reduced carpet waste is mixed or coated with abinder to produce material that is subjected to temperature and/orpressure to yield composite material. The size reduction process maytake place at the same facility where the PCs are manufactured, or thecarpet waste may be processed at a first facility and delivered to asecond facility for incorporation into the PC products. Post-manufacturetreatments for the composite material are also described below.

The carpet waste is made up of selvedge, post-industrial carpet waste,post-consumer carpet waste, or waste carpet reclaimed from landfills.Post-industrial carpet waste refers generally to waste material producedas a byproduct to the manufacturing process, such as trimmed carpetsegments, as well as to carpet that fails to pass quality or otherinspections, thus rendering it unsuitable for consumer use.Post-consumer carpet waste refers generally to carpet waste that isgenerated during installation at a consumer site or that is removed froma consumer site during demolition and/or replacement. Regardless, theterms selvedge, carpet waste, waste carpet, reclaimed waste, recycledwaste, and similar terms are used herein interchangeably and may be usedin the processes described herein interchangeably. These materialsgenerally will be in baled form to begin the size reduction phase of thepre-processing. The bales vary in size but usually are about 1000 lb. toabout 2000 lb. All of the equipment described in the carpet reductionprocesses below may be supplied by Pallmann Maschinenfabrik GMBH, ofother manufacturers that produce similar equipment. Alternativemanufacturers of specific equipment are identified below.

The first step in the size reduction phase includes reducing the wasteto a manageable size for the remainder of the process. As depicted inFIG. 2 , either a combination of a shredder/chopper and grinder (ProcessOption A), or a major capacity grinder (Process Option B) is used toprocess the materials to smaller sizes. Process Option A may be used toreduce carpet waste to pellets or granules that may be further processedinto various PC products. The shredder/chopper first reduces theselvedge or carpet waste to chunks approximately three inches square(3″×3″), although other sizes are contemplated, depending on theequipment used. In addition to Pallmann Maschinenfabrik, theshredder/chopper may be manufactured by Vecoplan, LLC, or Weima America,Inc. The shredded material then passes through a grinder which furtherreduces the chunks to a fiber fluff material with a diameter of thefibers similar to the diameter of the original carpet fibers and alength of about 0.25″ to about 1″. Other manufactures of comparablegrinders include Vecoplan, LLC, Cumberland Engineering Corp., andRepublic Machine, Inc.

The waste optionally can be run through a separator which acts as ahammer mill/cyclone to remove the dirt from the carpet waste. In thisstep, some of the carpet backing containing inorganic fillers may alsobe removed. Generally, however, it is unnecessary to deliberatelyseparate the various carpet components prior to incorporating therecycled carpet waste into PCs. All of the components of carpet may beused, not only one component, such as the carpet fibers, as certainknown methods disclose. Thus, manufacturing time is decreased, since thestep of component separation is not utilized. The slightly-size reducedmaterial, due to the hammer mill effect, is ready for the next step, theagglomeration process, while the dirt and carpet backing materials thatmay have been removed from the small chunks are disposed. Carpet backingthat is not removed, however, does not have any adverse effect whenincorporated into a PC using recycled carpet waste. The fiber fluff,regardless of the use of the separator or not, also may be blended withother materials such as wood or natural fibers, synthetic fibers (i.e.,fiberglass), inorganic fillers, or other reinforcing fillers. The fiberfluff material or the blended material is then conveyed to theagglomeration step.

The agglomeration of the above materials occurs inside the agglomerator.The materials enter a horizontal drum containing a revolving rotor thatis shaped so as to force the fiber fluff or blends against the drumwall. The drum wall is perforated so that, as the rotor forces thecontained materials against the perforated wall, the material is forcedthrough the perforations, thereby forming strands of a fixed diameter.On the outside of the drum are stationary knives which cut the strandsinto a fixed length. During this process, the material is heated byfriction to a temperature that remains below the melting point of thehighest melting point material in the blend. The temperature iscontrolled by the speed of the rotor, the diameter of the perforations,and the thickness of the drum wall. As each component of the carpetwaste, i.e., backing and carpet fibers, is pressed against the wall ofthe drum, that material heats up due to friction, until the materialsufficiently softens, such that it is then pressed through theperforated drum by the rotor. The agglomerating machinery could bereplaced by a pellet mill manufactured by Bliss Industries or CaliforniaPellet Mill Co.

The granules that are formed in the agglomeration step are generallycylindrical in shape and approximately 0.125″ in diameter and about0.125″ to about 0.25″ long. The diameter and length of the granules canbe modified by changing the diameter of the holes in the drum walland/or changing the speed of the rotation against the knives. Becausethe granules are hot when they are formed and cut to length, some of thegranules may be stuck to one another. Therefore, for better sizeconsistency, the granules next pass through a grinder which separatesany stuck granules. This grinder step may also be used to reduce thesize of the granules, and/or the granules may be further reduced in sizeby a pulverizer. For example, if the final desired dimension is lessthan 0.125″, the pulverizer may be used to reduce the particle size to8-16 mesh. This is the equivalent of about 0.04″ to about 0.10″.

As an optional step, the granules or pulverized particles may befiberized. The fiberizing process includes a mechanical roughing of thesurface so that the surface takes on a fuzz-like characteristic that maybe desirable for the composite product process described below. Afterprocessing to the desired condition, the material is then sent to thecomposite production process.

As an alternative to the above process, Process Option B may be used toreduce carpet waste to a fiberized mass. First, a major capacity grinderreduces the carpet waste to fibers about 0.25″ to about 1.0″ in lengthand about 1/32″ to about 0.125″ in diameter may be utilized. Theserandom-sized fibers are ready for the agglomeration process or foralternative processes not requiring agglomeration. Next, the materialoptionally may be passed through a separator, as described above. Thefibers may then be passed through the agglomeration process as describedabove, or the fibers may pass directly to the fiberizer equipment.Again, the fiberizer changes the surface characteristics of the fibers,giving them a fuzz-like surface with greater surface area and adifferent bulk density. The fiberizing step is again optional, and maynot be required for all end uses of the composite products. Next, thefibers pass through a blender where wood or natural fibers, syntheticfibers (i.e., fiberglass), inorganic fillers, or mineral fillers (ifany) may be added. Once the blending of the fibers and added materialsis complete, the blend is ready for the composite production process.

Significantly, it has been determined that it is not necessary toseparate or classify the various materials contained in selvedge orcarpet waste, even though most carpet surface materials are nylons,polyester, polypropylene, or wool and the backing material is usuallypolypropylene and/or highly filled synthetic latex. These materialsexhibit considerably different physical properties and processingproperties, but the entire waste product may be used in the compositesheet material, regardless of the differences in the components thatcomprise the carpet waste. The waste carpet, having been made into anagglomerate, a fiberized agglomerate, a pulverized agglomerate, afiberized, pulverized agglomerate, a fiberized fluff, etc., becomes thebase material for the composite product. Additionally, other waste fiberor fiberized waste fiber may also be used to manufacture a compositeproduct. The whole range of materials in carpet waste may be part of thecomposition.

After the size reduction process(es), the carpet waste is ready to beformed into composite sheets, a process for which is depicted in FIG. 3. The carpet waste materials may be loaded into a large rotating drum ora drum with rotating mixing blades and/or a resination blow line. Thisequipment is used to coat the carpet waste with a binding agent. Othermaterials such as natural fiber fillers or inorganic fillers may beloaded with the carpet waste material. If the material is loaded into adrum, water and/or a binding agent (such as MDI) are sprayed out of theresination blow line to coat the materials, while the drum and/or bladesspin to cause the material within to become evenly distributed. Theaddition of water may achieve a desired moisture content for thematerial and prepare the material for the binding agent. For theresination blow line method, the material is blown through a tube thathas water and MDI introduced into it. The blowing action causes the airto become turbulent which allows the water and MDI to evenly coat thematerial. In one embodiment, the binding agent is applied in this mannerto the granules or fibers at a concentration of about 1% to about 20% ofthe total weight of the granules plus any other additives.Concentrations between about 2% to about 10% and about 5% to about 6%are also contemplated. Generally, higher concentrations of resin producecomposite sheets with higher moduli of elasticity and rupture. Thiscoated carpet waste dries rapidly under ambient conditions, allowing thegranules or fibers to continue to flow without adhering to one another.Accordingly, once coated and dried, the resin coated particles need notbe used immediately, and may be stored and/or transported for later use.

The MDI-coated carpet waste and other additives (if applicable) areconveyed to a mat forming station that includes conveyors, meteringscales, spreader heads and a control management system. The spreadingequipment distributes the material onto a forming belt such that thespread material becomes a mat which has a generally uniform thickness,width and initial density. Board properties may be determined by theshape of the carpet waste composite particles/fibers and by theirposition in the formed mat. Additionally, the forming station candistribute more than one type of material for a multi-layered board. Forexample, the spreader head in the forming station could spread a mat offibers on the forming belt, then a second spreader head could spread amat of pellets on top of the fibers, then a third spread head couldspread a top layer of fibers onto the pellets. Many differentcombinations of materials can be spread onto the forming belt to makevarious types of boards. The number of layers per board also can bevaried. For example, a board could be manufactured to have an outerlayer of carpet waste with a fiberglass core, or an outer layercomprising carpet waste pellets, and carpet waste fiber underlayers witha carpet waste pellet core.

After the mat is spread formed, the forming belt then transports the matinto a pre-heater, a pre-press, or directly to a press machine. Thepre-heater and pre-press may be utilized to reduce total processing timeof the composite sheet. Due to the thermal inertia and thickness of thematerial, heat from the press platens or rolls may take longer topenetrate the total thickness of the mat, thereby extending process timeand costs. Preheating brings the temperature of the entire mat up to ahigher starting temperature. The pre-press compresses the startingmaterials to a thickness that is more appropriate for introduction intothe final presses and, additionally, the pre-heater and pre-press may bea single unit or separate units. In certain embodiments, the temperatureof the mat can be elevated from about 65° F. to about 200° F. beforeentering the board forming process. This rapid heat transfer to thecarpet waste may be accomplished by microwaves or by the injection of asteam/air mix (moist air) alternately from either surface into the mat.The steam condenses during this process, transferring the heat into themat. The pre-heater may also pre-press or compress the material beforeit enters the board forming process. The heated mat is then transferredby an intermediate belt conveyor to the compression section of theinfeed end of a continuous roll press or into a cycle press which is thebeginning of the board-forming process.

In one embodiment, composite sheets are manufactured using a cyclepress, which may have single or multi-daylight openings. Ranges ofvarious process parameters for manufacturing various embodiments of PCsutilizing recycled carpet waste in a cycle press are presented in TableA-1, below. The composite material is transferred into the cycle presswhere it is subjected to temperature and pressure from a top and bottomplaten that compresses the mat to a predetermined thickness or height.The elevated temperature and pressure activates the binding agent and,depending on the temperature, melts certain of the carpet componentswhile leaving others unmelted, to produce in a finished board or sheet.During the cycle press process, steam may be injected into the mat toensure thorough heating of the binding agent and bonding of thecomposite material. The cycle press may also use an active cooling cycleto reduce the temperature of the board before it exits the press. Theplatens may be engraved with a pattern to give the board outer surface astructured pattern.

TABLE A-1 Composite Sheet Processing Parameters (Cycle Press) Range HighLow Total Time for heating material, during 360 60 press-cycle [sec]Temperature of Heating Plates 600 100 [° F.] Pressure of Heating Press[psi] 6000 150 Internal Temperature of Board [ ° F. ] 500 340 Cure Time[sec] 30 5 Transition Time from Heating 600 0 to Cooling Press [sec]Total Time for cooling material, 360 60 during press-cycle [sec]Temperature of Cooling Plates 300 32 [° F.] Pressure of Cooling Press[psi] 6000 150 Internal Temperature of Board [ ° F. ] 300 70

Heat is generally delivered to the platens in the form of hot water,steam, electric coils, or circulating heated chemicals. In certainembodiments of the process, the platens may be heated from about 100° F.to about 600° F. Temperature ranges from about 200° F. to about 550° F.,and about 340° F. to about 420° F. also may be desirable. Additionally,temperature ranges from about 420° F. to about 550° F. may be utilized.Final internal temperatures of the composite being compressed within thecycle press will be dependent at least in part on the temperature of theplatens and compression time. If left in the cycle press for asufficient period of time, the internal temperatures of the compositematerial will generally equal those of the platens, the ranges of whichare given above. Final internal temperatures up to about 250° F., about300° F., about 340° F., about 350° F., about 400° F., about 420° F., andabout 480° F. have produced composite sheets displaying acceptableperformance. Unlike known recycled carpet waste composite sheet materialmanufacturing processes, which heat the composite sheets to atemperature below the melting points of the carpet fibers and othercarpet components, it has been discovered that heating the carpet wasteto higher temperatures may be desirable. For example, temperatures ofapproximately 340° F. will melt polypropylene, a component in manymodern carpet constructions, without melting any nylon fibers (that meltat about 420° F.). The melted polypropylene, combined with binding agentresins of the types disclosed herein, form a sheet material having verydesirable properties. The unmelted nylon provides additional structuralstrength to the finished composite and may increase flexural strength,though completely melting the carpet fibers can also produce a PCdisplaying acceptable performance properties. Pressures applied by theplatens in the heating press may range from about 150 psi to about 6000psi or greater, to obtain a the desired thickness and density.

The cycle press may include channels within the platens that thereaftercirculate water or chemical coolant(s) to reduce the temperature of theboard. The water or coolants may be chilled and volumetric flow ratescontrolled to reduce the total cooling time for the board to achieveacceptable manufacturing cycle time. This cooling step may take place inthe heating press or the board may be transferred from the heating pressto a cooling press. If the board is transferred from the heating pressto the cooling press, the transfer time should be minimized to avoidwarping of the PC. It has been determined that transfer time of lessthan about 600 seconds are acceptable. The cooling platens may have atemperature range of about 300° F. to about 32° F. Cooling temperatureranges from about 390° F. to about 65° F. may also be desirable. Rangesfrom about 250° F. to about 180° F. may also be utilized. If left in thecycle press for a sufficient period of time, the internal temperaturesof the composite material will generally equal those of the platens, theranges of which are given above. Final internal temperature of as highas 300° F., however, may be desirable to minimize warping of thecomposite sheet. Additionally, final internal temperatures of about 100°F., about 80° F., and about 70° F. have produced composite sheetsdisplaying acceptable performance. The board is rapidly cooled underpressure to maintain its flatness. Due to its high polymer content, theboard will usually warp if allowed to cool unrestrained using ambientair. Pressures applied by the platens in the heating press may rangefrom about 150 psi to about 6000 psi or greater.

Table B presents the ranges of various components that may be utilizedin composite formulations to produce acceptable PCs. Specifically,materials utilized may include colorants, wood filler, fire retardants,fiberglass, mold inhibitors, binders, and recycled carpet waste. Therecycled carpet waste can be about 20% to about 98% of the total formulaweight and still retain acceptable physical properties in the compositesheet. Certain embodiments may include carpet wastes in the amount ofabout 90% to about 98% total weight. Still other embodiments may includecarpet wastes in the amount of about 94% to about 95% total weight. Ithas been found that composites that utilize approximately 95% carpetwaste and about 5% binding agent produce a composite that exhibitssatisfactory performance while being economically advantageous, due tothe low cost associated with using recycled carpet waste versus virginmaterials. In other embodiments, a 9:1 ratio of carpet waste to MDI, upto a 49:1 ratio of carpet waste to MDI may be utilized. Table B alsopresents percentages of additives, such as wood filler, color, fireretardant, fiberglass, and mold inhibitor that may be added to thebinder/carpet waste mixture. The percentages of these additives may beup to those identified in Table B, relative to the carpet waste/MDIcontent. Additionally, there is no discernible difference in theperformance of the composite when using recycled carpet waste obtainedfrom post-industrial carpet waste or post-consumer carpet waste, ascompared with using virgin materials.

TABLE B Formulation Ranges for Composite Sheets Range Low High Material% % Carpet Waste 80 98 Moisture Content 0 10 Additives: Binders: MDI 220 UF 2 20 MF 2 20 PF 2 20 Wood filler 0 65 Color 0 25 Fire Retardant 025 Fiberglass 0 50 Mold Inhibitor 0 25

Tables C-1 to C-4 present formulations and performance parameters forPCs made in accordance with the cycle press process described above.Tables C-1, C-2, and C-3 present this information for PCs made withdifferent types of binding agents, but having the same total percentageof binding agents. The water absorption, thickness swell and moisturecontent testing was performed in accordance with the ASTM D1037-96Atesting standard. The PC described in Table C-1 is made with MDI and hashigher modulus of rupture (MOR) and modulus of elasticity (MOE) values,with lower moisture absorption properties.

TABLE C-1 Example 1 Formulations and Performance Properties Material %Carpet Waste 90.2%  Moisture Content 4.8% Additives: Binders: MDI 5.0%UF 0.0% MF 0.0% PF 0.0% Wood filler 0.0% Color 0.0% Fire Retardant 0.0%Fiberglass 0.0% Mold Inhibitor 0.0% total 100%  Thickness (inch) 0.250Density (pcf) 53.3 MOR (psi) 1,866 MOE (psi) 80,331 Tensile -Perpendicular [IB] 728 (psi) Tensile - Parallel (psi) 14 LinearExpansion 0.10%  Thickness Swell (inch) 0.002 Thickness Swell (%) 0.00% Moisture Content (%) 0.27% 

Table C-2 presents information for a PC utilizing PF as the bindingagent, that results in significantly lower, though still acceptable, MORand MOE values.

TABLE C-2 Example 2 Formulations and Performance Properties Material %Carpet Waste 90.2%  Moisture Content 4.8% Additives: Binders: MDI 0.0%UF 0.0% MF 0.0% PF 5.0% Wood filler 0.0% Color 0.0% Fire Retardant 0.0%Fiberglass 0.0% Mold Inhibitor 0.0% total 100%  Thickness (inch) 0.250Density (pcf) 48.0 MOR (psi) 971 MOE (psi) 49,600 Tensile -Perpendicular [IB] 716 (psi) Tensile - Parallel (psi) 58 LinearExpansion 0.54%  Thickness Swell (inch) 0.007 Thickness Swell (%) 2.97% Moisture Content (%) 4.12% 

Table C-3 presents information for a PC manufactured with a mixture ofMDI and UF as binding agents. While this formulation displaysperformance characteristics higher than those listed for the Table C-2sample, the performance values are not as high as the sample using MDIas the binding agent, presented in Table C-1.

TABLE C-3 Example 3 Formulations and Performance Properties Material %Carpet Waste 90.2%  Moisture Content 4.8% Additives: Binders: MDI 1.25% UF 3.75%  MF 0.0% PF 0.0% Wood filler 0.0% Color 0.0% Fire Retardant0.0% Fiberglass 0.0% Mold Inhibitor 0.0% total 100%  Thickness (inch)0.250 Density (pcf) 45.4 MOR (psi) 1,359 MOE (psi) 66,716 Tensile -Perpendicular [IB] 1002 (psi) Tensile - Parallel (psi) 44 LinearExpansion 0.31%  Thickness Swell (inch) 0.007 Thickness Swell (%) 2.78% Moisture Content (%) 3.02% 

Table C-4 presents a composite sheet utilizing 25% wood filler, withdouble the amount of binding agent utilized in the Table C-1 throughTable C-3 samples. Estimates of the performance properties of thissample utilizing wood filler are identified with an asterisk.

TABLE C-4 Example 4 Formulations and Performance Properties Material %Carpet Waste 60.0%  Moisture Content 5.0% Additives: Binders: MDI10.00%   UF 0.00%  MF 0.0% PF 0.0% Wood filler 25.0%  Color 0.0% FireRetardant 0.0% Fiberglass 0.0% Mold Inhibitor 0.0% total 100%  Thickness(inch) 1.000 Density (pcf) 66.7 MOR (psi) 2,815 MOE (psi) 236,000*Tensile - Perpendicular [IB] (psi) 1500 *Tensile - Parallel (psi) 100*Linear Expansion 0.40% *Thickness Swell (inch) 0.010 *Thickness Swell(%) 3.00% *Moisture Content (%) 3.00%

The differences in the performance properties of the above-identifiedexamples indicate that the types and amounts of binders may be varied asdesired to achieve acceptable results. Binder type and amount may bevaried to effect cost or other properties. Although particularembodiments have not yet been tested, additives such as fire retardantsmay be added to produce a composite sheet having a Class A fire rating.

According to an alternative embodiment, the PC may be manufactured usinga continuous roll process. The continuous roll press is a double beltedpress capable of maintaining a range of temperatures and pressures onthe mat to allow the binding agent reaction and melting of selectcomponents to take place. The continuous roll press belts may be steelor other material. Process parameters for a continuous roll press aredepicted in Table A-2. Temperatures utilized are generally similar tothose utilized in the cycle press process.

TABLE A-2 Composite Sheet Processing Parameters (Continuous Roll Press)Range High Low Temperature of 600 100 Heating Rolls [ ° F. ] Pressure ofHeating Rolls [psi] 6000 150 Internal Temperature of Board 500 340 [ °F. ] Temperature of Cooling Plates 300 32 [° F.] Pressure of CoolingRolls [psi] 6000 150 Internal Temperature of Board 300 70 [ ° F. ]

For example, pressures from about 150 psi to about 6000 psi are used tosqueeze the fiber mat to the desired thickness and density of the finalproduct. The continuous roll press consists of a press structure thattensions the belts. In general, the press includes a number of frameunits, depending on the length of the press and pressure that isrequired for a particular application. Cylinders arranged at the frameunits in various combinations exert the desired pressure. The pressincludes top and bottom heated platens which roller rods and the beltstravel over. The press has an infeed head to guide the roller rods,belts and mat to be pressed. The roller rods are located between theheated platens and the belts and support the mat as it is moved from onecylinder to the next. The belts are driven by two or more drums atgenerally opposite ends of the roll press. Drum scrapers may be used tokeep the board from sticking to the belts. A release agent also may besprayed onto the belts to keep the mat from sticking to the belts,allowing the composite to exit easily the press at the completion offorming. A control system regulates the operation of the press, such asthe speed of the belts, temperature, pressure, thickness of the mat,etc.

The continuous roll press transfers heat to the binding agent-coatedcomposite material. As the heat activates the coating, the cylinderspress the mat together to achieve the desired thickness. Thus, while themat material moves from the infeed section of the press, the mat'sthickness is reduced while being heated to a temperature that ensuresactivation of the binding agent and melting of certain fibers. As themat moves through the continuous roll press, the platens graduallyreduce the thickness of the mat to a predetermined thickness. Dependingon the amount of material introduced to the infeed section of the press,the density of the finished board is directly related to its finalthickness.

After the binding of the material and desired height dimension of themat has been reached in a continuous roll press, a board is formed whichis in the shape of a continuous ribbon. When the ribbon exits the press,it undergoes a continuous edge trimming operation to reach the desiredwidth and then it is cross-cut to a pre-selected length. The ribbon istransported through the trimming and cross-cutting operations by aroller conveyor and pinch rollers. The cut boards are then transportedto a cooling station. The cooling station can employ a variety ofdifferent machines such as a star cooler, with subsequent stacking, or astacking roller conveyor. The star cooler is a large diameter wheel withmultiple rows of spoked arms extending from the wheel. The arms lifteach board from the conveyor and allow the boards to rotate with thewheel and be air cooled. If needed, the continuous roll press can have acooling section with chilled rollers near the press outlet. This willcool the board (as described above) eliminating the need for furthercooling. The board is then conveyed to a stacking operation and storedfor future use. Alternatively the boards may be conveyed to a separatecooling press as described above. The boards are now ready to be shippedor they can go through a variety of decorating alternatives.

FIG. 4 shows the finishing and decorating steps that may be employedfollowing cutting to final width. The composite product can now beprocessed further to change the cross-sectional profile to take on theshape required in the finished product. The processing can be done on avariety of cutting machines of different designs, the most common ofwhich is a molder using rotating knives. This machine allows for thesetting of the knife blades to adjust the cut to the desired profile.Another common device is the router which cuts a specific groove orgrooves (routs) into the surface of the composite product. The routerhas the same effect as the molder in that it changes the initial profileout of the process into the desired profile required for the finalproduct.

The profile may also be changed using thermoforming methods. In thiscase, the composite product is placed in a mold of the desired profileand with heat and pressure the product takes on the shape of the mold.This profile change offers an additional decorating capability in thatthe desired color and/or pattern may be on a transfer foil placed in themold. With the application of the heat and pressure during the process,the color and/or pattern are transferred from the carrier foil to thecomposite product. Thus, at the end of the thermoforming process, thecomposite product has the desired profile and also the desireddecoration.

The composite product may be embossed after manufacturing. The embossingis accomplished with an embossing plate or roll. The plate or roll hasthe pattern to be transferred to the product on the surface of the plateor roll. This surface is heated to a temperature that will soften thesurface of the composite product. Then the plate or roll is pressed ontothe surface of the product to give the desired pattern transfer. As thesurface of the composite product cools, the embossed pattern becomesfixed on the surface of the composite product. The embossed compositeproduct is now ready to be coated, or if no coating is required for theend-use product, it is ready for packaging.

Composite products that will be decorated first pass through a sander.This smoothing of the surface prepares the product for coating,transfers, and laminating. The sanded or embossed composite product maybe coated with primers, finish paints, or stains. The coatingapplication employs various conventional spray techniques using exhaustsystems to remove the excess spray and solvents. Either penetrating orfilm-forming coatings may also be applied, and the choice is dependenton the desired finished product appearance and application. The sandedcomposite product can also act as a core to which decorative andprotective layer(s) may be hot stamped from a foil or film or laminatedto achieve improved physical and visual enhancement. In this regard,U.S. patent application Ser. No. 11/054,258, filed Feb. 9, 2005, andpublished as U.S. Patent Application Publication No. 2006/0147693, andU.S. Provisional Patent Application Ser. No. 60/641,308, filed Jan. 4,2005, describe exemplary processes and are incorporated by referenceherein in their entireties.

The composite product also may be decorated using transfer foils. Onceagain the product is first sanded to smooth the surface, then anadhesive layer is applied to the profile using a conventionalapplication technique. The transfer foil has the desired color and/orpattern on a polymeric substrate, and is brought into contact with thesurface of the product using stamping equipment designed for thespecific application. Using heat and pressure, the color and/or patternis transferred from the foil to the product. The heat required for thetransfer activates an adhesive layer on the surface of the profileensuring bonding of the decoration to the profile. With the color and/orpattern now on the composite product, the spent foil is then collectedfor disposal, and the finished product has the desired decorated effect.

Another decorating method that may be employed is lamination. Severalmaterials may be used as the laminate surface, such as wood veneers,synthetic veneers, foils, films, and polymeric sheets. The applicationof rigid laminates like wood veneers is done using conventionallaminating equipment. Generally, an adhesive system (either a wetadhesive system or a hot-melt adhesive system) employing a primer and anadhesive is applied to the PC substrate. The rigid surface laminate isthen applied to the substrate and temperature and pressure are applied.After the temperature-pressure step, the laminated product is then setfor a fixed period of time to allow the adhesive system to cure. In thecase of the composite product, the composite product is the substrate.The adhesive system, usually a hot-melt adhesive, is applied to thecomposite product. The rigid veneer is then placed on the adhesive layerforming a sandwich of composite product, adhesive, and rigid laminate.The sandwich is then pressed to secure the bond of the laminate to thecomposite product. After curing the laminated product with the desireddecorative appearance is ready for packaging.

Another laminating technique used with the composite product is foillaminating. This technique can be referred to as wrapping; wherein, thecomposite product profile is wrapped in the decorative foil. After thecomposite product profile has been sanded, the profile passes through awrapping device that takes the foil wrap from a coil then applies theadhesive (and primer, if required) to the foil. In a continuous process,the foil wrap is then passed over the composite product profile. Using aseries of rollers, the foil wrap is shaped to the composite productprofile. The foil wrap may incorporate an integral topcoat material,such as polyurethane, acrylic, or other protective materials, forphysical property enhancement. If, however, the foil wrap integratesonly the decorative elements, then the wrapped composite product willrequire a separate topcoat for certain applications.

If the end-use product application requires significant surface propertyenhancements, such as abrasion resistance, a topcoat may be added to thedecorating process. The topcoat can be polyurethane, acrylic, or otherprotective material that will impart better physical properties to thesurface of the wrapped finished product. The topcoat may be sprayapplied or hot melt applied. If spray applied, the wrapped compositeproduct will pass through a spray applicator and then may or may notpass through a curing device, such as an ultra-violet radiation station.If the topcoat is hot melt applied, then a layer of polyurethane isapplied to flat surfaces of the decorated composite product. The cureprocess for this type of material is time dependent and could takeseveral days depending on the hot melt topcoat chosen for a specificend-use application for the completed finished product.

A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention.Accordingly, other embodiments are within the scope of the followingclaims.

What is claimed is:
 1. A composite building material, comprising: afirst layer comprising: a processed carpet waste comprising a reducedamount of inorganic filler relative to an amount present within anunprocessed carpet waste; and a first binding agent in intimateassociation with the processed carpet waste; and a second layer disposedon the first layer and comprising natural fibers and a second bindingagent.
 2. The composite building material of claim 1, wherein the firstbinding agent comprises at least one of methylenediphenyldiisocyanate(MDI) or a product of a reaction involving methylenediphenyldiisocyanate(MDI).
 3. The composite building material of claim 1, wherein the secondbinding agent comprises at least one of phenol formaldehyde (PF) or aproduct of a reaction involving phenol formaldehyde (PF).
 4. Thecomposite building material of claim 1, wherein the carpet wastecomprises carpet fibers having a length from about 0.25 inches to about1.0 inch.
 5. The composite building material of claim 1, wherein thecarpet waste comprises carpet fibers having a length of about 1.0 inch.6. The composite building material of claim 1, further comprising atleast one of a patterned surface, a cover layer, or a sanded surface. 7.The composite building material of claim 6, wherein the patternedsurface comprises at least one of a molded surface, an embossed surface,a colored surface, or a wood grain pattern.
 8. The composite buildingmaterial of claim 6, wherein the cover layer comprises a coatingselected from the group consisting of primers, paints, stains,polyurethane, and acrylic.
 9. The composite building material of claim1, further comprising at least one of a molded patterned surface, anembossed patterned surface, or a hot-stamped layer.
 10. The compositebuilding material of claim 1, further comprising additional inorganicfiller relative to an amount present in the processed carpet waste. 11.The composite building material of claim 1, further comprisingfiberglass.
 12. The composite building material of claim 1, wherein thecomposite building material comprises polypropylene.
 13. The compositebuilding material of claim 1, further comprising a third layer disposedon an opposite side of the first layer and comprising natural fibers andthe second binding agent.
 14. A method of manufacturing a compositebuilding material, the method comprising the steps of: forming a firstlayer comprising: a processed carpet waste comprising a reduced amountof inorganic filler relative to an amount present within an unprocessedcarpet waste; and a first binding agent in intimate association with theprocessed carpet waste; applying a second layer to the first layer, thesecond layer comprising natural fibers and a second binding agent; andheating and pressing the first layer and the second layer together toform the composite building material.
 15. The method of claim 14,wherein the first binding agent comprises at least one ofmethylenediphenyldiisocyanate (MDI) or a product of a reaction involvingmethylenediphenyldiisocyanate (MDI).
 16. The method of claim 14, whereinthe second binding agent comprises at least one of phenol formaldehyde(PF) or a product of a reaction involving phenol formaldehyde (PF). 17.The method of claim 14, wherein the carpet waste comprises carpet fibershaving a length of about 1.0 inch.
 18. The method of claim 14, furthercomprising adding at least one of a patterned surface, a cover layer, ora sanded surface to the composite building material.
 19. The method ofclaim 18, wherein the method comprises adding the patterned surface, andwherein the patterned surface comprises at least one of a moldedsurface, an embossed surface, a colored surface, or a wood grainpattern.
 20. The method of claim 18, wherein the method comprises addingthe cover layer, and wherein the cover layer comprises a coatingselected from the group consisting of primers, paints, stains,polyurethane, and acrylic.
 21. The method of claim 14, furthercomprising adding at least one of a molded patterned surface, anembossed patterned surface, or a hot-stamped layer to the compositebuilding material.
 22. The method of claim 14, wherein forming the firstlayer comprises adding inorganic filler relative to an amount present inthe processed carpet waste.
 23. The method of claim 14, wherein formingthe first layer comprises adding fiberglass.
 24. The method of claim 14,further comprising applying a third layer to an opposite side of thefirst layer, the third layer comprising natural fibers and the secondbinding agent.